The present invention relates generally to apparatus for sealing the foldable flaps of cartons by applying a strip of self-adhesive tape material along the edges of the flaps and, more particularly, to a system for forming a pull tab at one end of the strip of tape as it leaves the tape head, to facilitate removal of the tape to gain access to the interior of the carton, and a mechanism for controlling the tracking of the tape in the tape head.
In the packaging industry, corrugated and fiberboard cartons have been used for many years and various machines have been developed which are capable of sealing such cartons either by glueing the flaps, taping the flaps, or by stapling or otherwise providing fasteners to maintain the flaps in a closed position. Many of these machines are designed to accept cartons of random width and height by providing various types of means to control the transverse movement of the side arm assemblies associated therewith and the vertical movement of the top sealing means. An example of such a machine is disclosed in U.S. Pat. No. 4,392,911, assigned to the same assignee as the present invention.
It is the typical practice to seal the top flaps of a carton by applying a strip of sealing tape that extends along the upper portion of the leading end panel, across the top of the carton in sealing relationship to the edges of the upper major flaps, and then down an upper portion of the trailing end panel. The strip of tape is pressed into sealing contact with the carton end panels and the major side flaps. When it becomes necessary to open such cartons, it is the typical practice to utilize a sharp implement, such as a knife, to slice open the carton. In so doing, the sharp implement may contact the goods in the carton causing damage thereto.
It has heretofore been proposed to form a tab section at one end of the strip of tape, as the carton is being sealed, which facilitates peeling off the tape to gain access to the interior of the carton. The present invention is directed to a simple, reliable, and inexpensive means for automatically forming a pull tab at the trailing end portion of the strip of tape as the carton passes through the taping head of a carton sealing apparatus. The present invention is further directed to an improved means for controlling the tracking of tape in the tape head.